1. Field of the Invention
The invention relates to a method of domain inversion parts and optical devices.
2. Related Art Statement
The polarity of a ferroelectric material is forcedly and periodically inverted to form domain inverted structure, so that an optical frequency modulator utilizing a surface acoustic wave and an optical waveguide conversion device utilizing non-linear domain inversion can be realized. Particularly, a wavelength converting device of a high efficiency can be produced by making it possible to convert periodically the polarity of a non-linear optical material. The device can be used for converting light such as solid laser so that a small and light-weight light source of a short wavelength can be provided to be used in applications such as printing, optical information processing and optical measurement and control.
It has been known so called electric field poling process for forming periodically domain inversion structure in a ferroelectric non-linear optical material. According to the process, a comb electrode is formed on one main face of a substrate of a ferroelectric single crystal and a uniform electrode is formed on the other main face, so that a pulse voltage is applied between them. Such method is described in Japanese patent publication 8-220578A.